Pattern drum indexing for circular knitting machines



8 Sheets-Sheet 1 FIG 2.

mvzmron: PE TER A MAH LER F. A. MAHLER PATTERN DRUM INDEXING FOR CIRCULAR KNITTING MACHINES 'iii i i j Dec. 6, 1966 Filed April 27, 1964 P. A. MAHLER PATTERN DRUM INDEXING FOR CIRCULAR KNITTING MACHINES 8 Sheets-Sheet 2 Filed April 27, 1964 ec. 6, 1966 P. A. MAHLER EEMAJ? PATTERN DRUM INDEXING FOR CIRCULAR KNITTING MACHINES Filed April 27, 1964 8 Sheets$heet 5 11w 6, ms 32%,43"?

PATTERN DRUM INDEXING FOR CIRCULAR KNITTING MACHINES P. A. MAHLER 8 Sheets-Sheet 4 Filed April 27, 1964 P. A. MAHLER Dec. M 1966 PATTERN DRUM INDEXING FOR CIRCULAR KNITTING MACHINES 8 Sheets-Sheet 5 Filed April 27, 1964 P. A. MAHLER 3,2fi9A-3? PATTERN DRUM INDEXING FOR CIRCULAR KNITTING MACHINES 8 Sheets-Sheet 6 Dec. 6,1966

Filed April 27, 1964 Dec. 6, 1966 P. A. MAHLER 3,289,437

PATTERN DRUM INDEXING FOR CIRCULAR KNITTING MACHINES Filed April 27, 1964 8 Sheets-Sheet '7 FIG! I.

P. A. MAHLER Dec. 6, 1966 PATTERN DRUM INDEXING FOR CIRCULAR KNITTING MACHINES 8 Sheets-Sheet 8 Filed April 27, 1964 FIGIG.

United States Patent 3,289,437 PATTERN DRUM INDEXING FOR CIRCULAR KNITTING MACHINES Peter A. Mahler, High Point, N.C., assignor to The Singer Company, New York, N.Y., a corporation of New Jersey Filed Apr. 27, 1964, Ser. No. 363,024 8 Claims. (CI. 66-50) The present invention relates to circular knitting machines having pattern selection drums for controlling the needles thereof to produce patterns by means of preselected arrangements of varied stitch forms, and more particularly to improved indexing mechanism for such drums.

The character of the stitch form produced on a needle at a knitting station is determined by the elevation of the needle as it enters the yarn feed station to take yarn. The fundamental stitch forms for producing a plain knitted tube, for use as the stocking blank for example, are obtained by cams operating directly on the needles through the conventional needle butts. In order to produce a pattern in the tube, the elevation of the needles is controlled by individual selector jacks associated with the needles and having a plurality of butt levels which determine the production of patterns by the presence or absence of a butt at selected levels on a particular jack. The jack is displaced by the engagement of a butt thereon with a jack actuator in the form of a slide controlled from a pattern selection drum which is conventionally common to all of the actuators. To vary the selection of jacks, the pattern selection drum is rotated in timed relation to the needle cylinder, for example by indexing the selection drum once or twice for each revolution of the needle cylinder.

Conventionally, in knitting a tubular stocking blank, the pattern drum is indexed from its starting point following completion of the turned welt at the start of the knitting of the blank, and completes one revolution during each knitting cycle wherein a complete tube is knitted, so that the drum is returned to its starting point for the start of the succeeding tube. Thus, when it is desired to knit tubes having a certain pattern sequence throughout its length, the pattern drum must be jacked or set up, to produce a particular pattern sequence.

With the foregoing in mind, the present invention provides a knitting machine wherein a single pattern drum may be set up or jacked to provide different patterns about its circumference, any one or more of which may be selected for knitting by a relatively simple alteration or adjustment in related mechanism.

More specifically, the present invention provides a knitting machine having a pattern selection drum operable to produce a variety of patterns and including separate mechanism operable to index the drum to activate a particular pattern, the timing of the drum being automatically correlated to the needle cylinder to insure proper actuation of the jack actuator slides.

The present invention provides drum indexing mechanism for a knitting machine which is readily adjustable to change the patterns which may be knit thereon, the mechanism being operable to insure properly timed relationship between the pattern drum and the cylinder thereby reducing substantially the down-time which is normally required for changes in pattern.

More specifically, the present invention provides a pattern selection drum indexing mechanism which insures displacement of the jack selector slides at the time when the needle cylinder is presenting jacks which are devoid of butts in registry with the selector slides which would interfere with the displacement of the slides.

The present invention provides for a pattern drum designed to be indexed at least twice for every revolution of the needle cylinder, indexing mechanism which insures that the first index of the drum occurs with the first portion of cylinder movement, and that the second index of the drum occurs with the second portion of cylinder movement.

All of the objects of the present invention are more fully set forth hereinafter with reference to the accompanying drawings wherein:

FIG. 1 is a view in side elevation of the upper portion of a circular knitting machine embodying the present invention;

FIG. 2 is a view in front elevation of a portion of the machine, as seen from the line 2-2 in FIG. 1, certain parts of the machine being hidden by cover members;

FIG. 3 is an enlarged view similar to FIG. 2, but with the cover members and certain other elements removed for the purpose of illustration;

FIG. 4 is a fragmentary sectional view of the right hand pattern drum with a portion of the associated mechanism broken away, as viewed from the line 4-4 in FIG. 3;

FIG. 5 is an enlarged transverse sectional view taken on the line 5-5 of FIG. 3, and illustrating selected mechanism associated with the rear pattern drum;

FIG. 6 is a diagrammatic development of the right hand pattern selection drum shown in FIGS. 1 to 5, and illustrating schematically a portion of the driving ratchet wheels associated therewith;

FIG. 7 is a cam development showing the cams operative on the needle butts and the selector jack actuator slides operative on the selector jacks associated with the needles, as seen from the interior of the cylinder;

FIG. 8 is a fragmentary enlargement of a portion of the diagram of the pattern jack layout in the right hand pattern drum as indicated by the bracket 8 in FIG. 6;

FIG. 9 is a view in side elevation of a pattern jack indicated at 9 in the diagram of FIG. 8;

FIG. 10 is a diagram of the butt arrangement for the needles, lifter jacks, and selector jacks in the needle cylinder, as seen from the outside of the cylinder.

FIG. 11 is an enlarged fragmentary sectional view taken on the line 11-11 of FIG. 5;

FIG. 12 is an enlarged sectional view taken on the line 12-12 of FIG. 5;

FIG.13 is an enlarged sectional view taken on the line 13-13 of FIG. 5;

FIG. 14 is a detached perspective view of a cam track controlling the indexing of the right and left hand pattern drums;

FIG. 15 is an enlarged fragmentary sectional view taken on the line 15-15 of FIG. 5;

FIG. 16 is a fragmentary sectional plan view taken on the line 16-16 of FIG. 15;

FIG. 17 is a fragmentary sectional view taken on the line 17-17 of FIG. 16; and

FIG. 18 is an enlarged fragmentary plan view illustrating the operation of the indexing mechanism of the present invention.

Referring now to FIG. 1, the knitting machine illustrated therein comprises a frame 20 having at its upper end a needle cylinder 21 rotatably mounted therein. A yarn guide ring 22, pivotally secured to the frame at 24, surrounds the upper end of the cylinder and mounts thereon a plurality of groups of yarn feed fingers, in the present instance, two. A rotary dial (not shown) overlies the open upper end of the needle cylinder 21 for simultaneous rotation with the needle cylinder through dial superstructure 23 mounted on the frame through a pivotal yoke 29. The dial is covered by a stationary dial cap which mounts the usual dial cams, yarn trimmer, and yarn control elements including a yarn-end suction takeoff which is connected to the suction side of a blower in the lower part of the frame 20 through a suction duct 25 including a yarn-end collector or trap 26. The knitting yarns are fed to the knitting stations from yarn packages 27 mounted on suitable creels or package supports 28 at the rear of the upper portion of the frame.

The needle cylinder 21 and the dial are driven by a conventional ring gear 31 connected to the main drive shaft 32 through suitable gearing including a clutch (not shown) for shifting between unidirectional rotation and reciprocatory rotation respectively. The main drive shaft 32 is driven from a drive motor in the lower portion of the frame 20 through suitable driving connections 33.

The sequential operations of the knitting instrumentalities of the knitting machine are controlled by pattern mechanism including in the present instance, three pattern control drums, a front drum 41, a rear drum 42, and an auxiliary drum 43, all of which are selectively indexed in timed relation to the rotation of the needle cylinder under the control of a conventional pattern chain or other master pattern control mechanism. During the course of the knitting of a complete stocking, blank, the needles 45 are individually controlled by a needle cam box 46 including cams operable on the butts of the needles, and by selector jacks 47 mounted in the cylinder 21 underlying the needles 45 and operable to selectively elevate the needles through lifter jacks 48 mounted in the needle cylinder intermediate the needles 45 and the selector jacks 47. The selector jacks, in turn, are actuated by actuators in the form of selector slides, in the present instance arranged in three arrays 51, 52, and 53 (see FIGS. and 7). The slides 51 are controlled from a right hand pattern selection drum 61 and the slides 52 are controlled from a left hand pattern selection drum 62. The slides 53 which constitute an array of six slides, are controlled separately through mechanism shown in part at 63 by one of the control drums, in the present instance, the front drum 41. In like manner, the lowermost six slides of the array 51 are controlled from the front drum 41 through linkages shown at 65 in FIG. 5, and the lowermost six slides of the array 52 are controlled from the rear drum 42 through linkages shown in part at 68, operating bell cranks 67. An individual draw-down slide 54 adjacent the group 51 is controlled from the rear drum 42 through a linkage 64.

The slides 51 and 52 are arranged insets of from four to eight slides each in the present instance six, and each set may be inactivated independently of its associated pattern selection drum by control mechanism operated from the front drum 41. The control mechanism for the array of slides 51, is designated generally 55, and the control mechanism for the array 52 is designated generally 56. In FIGS. 1 and 2, the control mechanism 55 and 56 are protected by cover members 57 and 58.

In accordance with the invention, means is provided to index the pattern drums 61 and 62 twice for every revolution of the needle cylinder so that two adjacent pattern jacks 100 in the pattern selection drum effect a selection of needles at the associated selector stations for one complete revolution of the needle cylinder which, in the present two-feed machine, embodies two courses of knitting. For example, the array 51 may select needles for knitting in the odd-numbered courses of the stocking and the array 52 may select needles for the even-numbered courses. If desired, the slide 54 and an upper slide 54a (see FIG. 7) may be used to repeat the selection previously made by the slides 51 in lieu of reselecting by means of the slides 52. The slides of array 53 correspond to the conventional gusset selector slides for use in knitting a reciprocated contoured heel and toe. Preferably, the slides 52 are used to control the jacks to produce overall patterns, such as meshes and the like which are normally produced on alternate courses only. The slides 51 may be controlled to produce spot patterns which are of short length and which appear at one or more localized areas along the length of the stocking blank.

In accordance with the invention the indexing of the pattern selection drums 61 and 62 is effected by ratchet devices controlled from an annular cam surface carried by the ring gear 31 of the knitting machine. The cam surface comprises a double cam track shown at 69 and 70 in FIGS. 5 and 14, each track having a single vertical rise about its circumference, the rise 169 for the track 69 being displaced 180 from the rise 170 for the track 70. As shown in FIG. 5, follower mechanism operates from the double cam track to index the pattern drums 61 and 62. The follower mechanism for the pattern drum 61 is designated 71 and includes a pair of connectors 72 and 73 respectively connected to pawl carriers 74 and 75 which are pivoted on the axis of the pattern drum 61 to cooperate with the ratchet wheels 78 and 79 fixed to the drum 61. As shown, the teeth of the ratchet wheels correspond in length to the spacing of two pattern jacks 100 and the pawls are displaced only the distance of a half-tooth. When the rise of the inner cam track 69 of the double cam track passes into registry with the follower mechanism 71, the connector 73 operates the pawl carrier 75 a distance to cause the associated pawl 77 to advance the drum 61 one step corresponding to the space of one pattern jack. After 180 of the needle cylinders revolution, the rise on the outer track 70 of the double cam track operates through the follower mechanism 71 including the connector 72 to displace the pawl carrier 74 a distance to cause its associated pawl 76 to index the rum 61 one step corresponding to the space of one pattern jack. A friction brake is provided on the drum 61 at 96 (see FIG. 17) to prevent the drum from overriding the pawl drive. Similar ratchet mechanism for the drum 62 is provided at 81 including connectors 82 and 83 and pawl carriers 84 and 85 having pawls 86 and 87 respectively operating on ratchet wheels 88 and 89 to index the drum 62 in a manner similar to the indexing of the drum 61.

In accordance with another feature of the invention stop mechanism is provided to interrupt the indexing of each drum, the stop mechanism for interrupting the indexing of the drum 61 being illustrated at 91, and the mechanism for interrupting the indexing of the drum 62 being illustrated at 92. As described more fully hereinafter, the stop mechanism is designed to arrest the drum at a predetermined point in its rotation, as determined by a foreshortened tooth in a selected one of the ratchet wheels. The stop mechanism displaces the pawl associated with the selected ratchet wheel to a position where it does not engage the foreshortened tooth and consequently, interrupts the advance of the ratchet wheel at that tooth. Since both pawls must be effective to cause continued indexing of the drum, interruption by either pawl arrests the indexing of the drum.

As pointed out previously, the slides in the arrays 51 and 52 are controlled by pattern jacks in the pattern selection drums 61 and 62 respectively, and further are capable of being rendered inactive in sets by the control mechanism 55 and 56 respectively. With reference to the slides 51, each slide is controlled by an operator in the form of a lever 101 pivoted on an upright shaft 102 and having a follower portion 103 operable to be engaged by a butt of the pattern jack 100 mounted in the selection drum 61. Each lever 101 is further provided with an extension 105 having a spring 106 associated therewith for biasing the follower portion 103 inwardly toward the pattern drum 61. Thus, for each half revolution of the needle cylinder, the position of the slide in the array 51 is determined by the absence or presence of a butt at the corresponding level on the pattern jack 100 in the pattern drum 61.

When it is desired to maintain a set of slides in inactive position, i.e., withdrawn from engagement with the butts on the selector jacks 47, the control mechanism 55 operates to displace the levers 101 associated with that set. To this end, the control mechanism includes a plurality of stops 111, equal in number to the number of sets of slides and operable to engage the extensions 105 of the levers 101. Each stop 111 is mounted on a bar 112 which is mounted for horizontal slidable movement in a support 113. The bar 112 is biased rearwardly by a spring 114 to a position normally affording actuation of the levers 101 by the pattern jacks 100 in the pattern drum 61. As shown in FIG. 3, the bar 112 is operated from the front drum 41 by means of a follower 118 and push rod 115 operating on a bell crank 116 pivoted to the support 113 and engaging at its opposite end a pin 117 on the bar 112. When a cam 119 on the drum 41 (see FIGS. 1 and 2) is in registry with the follower 118, the rod 115 is displaced upwardly, thereby pivoting the bell crank 116 clockwise to displace the bar 112 to the left against the bias of the spring 114. In the basence of a cam 119 on the drum 41 in registry with a follower 118, the associated push rod 115 permits counterclockwise movement of the corresponding bell crank 116, affording rightward displacement of the bar 112 by the spring 114, thereby rendering the levers 101 associated with the stop 111 in condition for actuation by the pattern drum. The control mechanism 56 comprises similar elements. With the foregoing arrangement, it is possible to provide several patterns on the selector drum 61 and 62, and to activate a particular pattern by proper arrangement of cams 119 on the front control drum 41.

FIGS. 6 to inclusive illustrate typical selector jack and pattern jack arrangements for providing pattern selectivity. For example, FIG. 10 illustrates a butt arrangement for the needles and jacks on the cylinder 21. Reading from the top of the figure, the first row indicates the needle butts 145 which vary in length about the circumference of the cylinder to cooperate with the needle cams in the cam box 46. The second row indicates the butts 148 of the lifter jacks 48 which cooperate with lifter jack cams (not shown) in a bed 152 intermediate the needle cam box 46 and the selector jack slides 51 and 52. In each of these rows in FIG. 10, each line indicates an individual butt, the length of the line indicating the length of the butt. The remainder of FIG. 10 indicates the butt arrangement on the selector jacks 47.

Adjacent the upper end of each of the selector jacks 47 is an upper guide butt 151 which rides on the underedge of the bed 152 and may selectively control needles through the medium of the slide 54a when the latter is displaced into active position. The butts 151 are arranged in two sectors, one sector comprising long butts designated L and the other sector comprising short butts designated S. It should be noted that with radially slidable cams, such as the slide 54a, the slide is advanced stepwise into active position. The first step of the advance occurs during the time when the sector of short butts is advancing past the slide, and the final step occurs during the period when the sector of long butts is advancing past and upwardly upon the slide so that when the short butts again pass the slides, the slide is fully inserted to elevate the short butts.

Spaced below the butts 151 on the jacks 47 are dn've butts 154. As shown in FIG. 10, the drive butts 154 are of uniform length to cooperate with fixed cams 155, 156 and 157 immediately beyond the selector slides 51, 52 and 53. The butts 154 are engaged with the cams 155, 156 or 157 by displacement of the jacks 47 through the medium of one or more of the selector slides 51, 52 or 53.

Below the drive butts 154 are selector butts arranged in three groups 161, 162 and 163. Each of the groups 161 and 162 comprise butts at thirty (30) patterning levels, the presence of a butt at a particular level being indicated by an X, and the absence of a butt being indicated by a blank. The group 163 comprises butts at six (6) other levels and the length of the butts are indicated in FIG. 10 by the designations L and S, the absence of a butt being indicated by a blank. The group 161 cooperates with the upper thirty slides and the group 162 arrays 51 and 52. The group 163 cooperates with the lower six (6) slides of the arrays 51 and 52 and also the entire array 53.

Below the group 163 and adjacent the bottom of the jack is a lower guide butt 164 which rides on the upper edge of a lower bed 165 and may be selectively engaged by the slide 54. It should be noted that the butts 164 are arranged in sectors of long and short butts which are opposite to the sectors of long and short butts of the butts 151.

The slides cooperating with the butts 151, 163 and 164 are inserted into action stepwise as noted above so that the butts may be arranged about the full circumference of the cylinder. The selector slides cooperating with the butts 161 and 162 at the patterning levels, on the other hand, are not displaced into their inserted position stepwise, but are displaced between their fully inserted and fully retracted position in one movement. In order to enable such movement without damaging the butts on the selector jacks, the butts in the groups 161 and 162 are confined to limited circumferential sectors of the cylinder. In the present instance, there are four hundred and one (401) selector jacks 47 disposed about the circumference of the cylinder and the group of butts 161 embraces one hundred and thirty-nine (139) of these jacks. The group 162, on the other hand, embraces the remaining two hundred and sixty-two (262) jacks. In this way, the slides for the groups 161 may be displaced freely without damage to the butts during that portion of the cycle when the 262 jacks are passing these slides. The slides for the butts 162 on the other hand, are displaced in that period when the 139 jacks are passing those butts.

The cams and slides which operate on the butts 145, 148, 151, 163, and 164 are all controlled from the pattern control drums 41, 42 and 43 whereas the selector slides which operate on the butts 161 and 162 are controlled from the pattern selector drums 61 and 62. As noted above, taking the selector drum 61 as an example, each slide 51 is controlled by a lever 101 having a follower portion 103 which may ride on a butt of a pattern jack mounted in the drum 61. The drum 61 is indexed a distance corresponding to the spacing of one pattern jack 100 each half revolution of the needle cylinder 21. One such index of the pattern drum 61 is'effected when the 139 jacks are passing the slides 51 and the other index is effected when the 262 jacks are passing the slides 51.

FIG. 8 is a diagram of a portion of the pattern selector drum 61 wherein a vertical line of squares indicates a single pattern jack, each square representing a butt level thereon, the darkened squares indicating the presence of a butt and the blank squares indicating the absence of a butt. As shown, the butts on the pattern jacks 100 are arranged in upper and lower groups 171 and 172 respectively corresponding to the groups 161 and 162 at the patterning levels of the selector jacks. Since there are two pattern jacks for each revolution of the cylinder, the butts in each group are arranged in pairs on adjoining jacks. The pairs in the group 171 are offset from the pairs in the group 172 by one jack. Thus, in the major pattern area in the drum 61, the jacks are numbered 100-1, 1002, 100-3, etc., reading from the right hand side. As shown in FIG. 8, the butts in the group 171 are identical on the jacks 1001 and 1002; and also on the jacks 1003 and 1004, and so forth. On the other hand, the butts in the group 172 are identical on the jacks 1002 and 1003, and also on the jacks 100-4 and 100-5, and so forth. It should also be noted that the arrangement and sequence of butts in the group 171 is identical to the arrangement and sequence in the group 172.

In accordance with the invention, as noted above, the drum 61 is indexed every half cycle of the cylinder. To

this end, the rises 169 and 170 are displaced 180 from one another. The rise 169 displaces the connector 73 a distance sufficient to displace the pawl carrier 75 an angular distance corresponding to a half tooth of the ratchet wheel 79. As the follower falls off of the rise 169, the pawl carrier is retracted a half tooth so that the pawl 77 rides half way up the next tooth. The displacement of the pawl indexes the drum the distance of the spacing of one pattern jack 100 and causes the ratchet 78 to advance so that the pawl '76 engages behind the tooth on the ratchet. After 180 of rotation of the cylinder, the rise 170 on the track 70 displaces the pawl carrier 74 the distance of a half tooth to thereby index the pattern drum the distance of the spacing of one pattern jack 100. This carries the ratchet wheel 79 the remaining half of its tooth spacing so that the pawl 77 engages behind the next tooth.

The teeth of the ratchet wheel 78 are in registry with the pattern jacks 100-1, 100-3, 100-5, etc. whereas the teeth of the ratchet wheel 79 are in registry with the pattern jacks 100-2, 100-4, 100-6 etc. Thus, indexing of the drum by the pawl 76 and ratchet wheel 78 displaces the pattern drum so that the follower portion 103 of the lever 101 travels from the odd-numbered pattern jacks onto the even-numbered pattern jacks. In like manner, indexing of the drum by the pawl 77 and ratchet Wheel 79 causes the fol-lower portions 103 to travel from the even-numbered pattern jacks to the odd-numbered pattern jacks.

It is noted that when the drum is indexed by the pawl 76 and ratchet 78 so that the follower portions 103 of the levers 101 shift from the pattern jack 100-1 to the pattern jack 100-2, the levers associated with the group 171 do not change whereas the levers associated with the group 172 do change. This index occurs during passage of the 139 selector jacks past the selector slide array 51 when there are no butts in the group 162, and accordingly, no interference with the changing of the levers by the pattern jack butts 172. The index by the pawl 77 and ratchet 79, which causes the follower portions 103 to travel from the pattern jack 100-2 to the jack 100-3, occurs when the 262 jacks are passing the slide array 51. This :latter index of the drum displaces the levers associated with the group 171 but maintains stationary the levers associated with the group 172. Thus, the butts on the selector jacks do not interfere with the displacement of the slides.

Since the indexing noted above is effected by the rises 169 and 170 on the cam tracks carried by the ring gear 31 of the knitting machine which also carries the needle cylinder 21, the pawl 76 and ratchet 78 operate only when the 139 selector jacks pass the slide array 51. By the same token, the pawl 77 and ratchet 79 are effective to index the drum only when the 262 jacks are passing the slide array 51. Thus, if one of the pawls is inactivated, or is ineffective to index the drum, during any portion of the knitting cycle, the drum 61 will not be indexed since both pawls 76 and 77 must be activated to index the drum. When both pawls are again activated, the indexing of the drum will resume automatically in properly timed relation to the needle cylinder.

Means is provided to arrest indexing of the pattern drum at predetermined points in its rotation. In the present instance, provision is made for arresting the drum at two predetermined points spaced approximately 180 from one another. To this end the ratchet sheel 78 is provided with a foreshortened tooth 178 and the ratchet sheel 79 is provided with a foreshortened tooth 179. And the stop mechanism is operated to position the poles 76 and 77 to avoid engagement of the foreshortened tooth.

As best shown in'FIGS. -18, the stop mechanism 91 comprises upper and lower stop plates 182 and 183 respectively. The plate 182 carries an upstanding pin 184 operable to engage the yoked end 186 of a bell crank 188 pivoted on a post 190 and operated by an operator 192 from a pattern control drum. The stop plate 183 has a depending pin adopted to engage the yoked end 187 of a bell crank 189 pivoted on the post and operated by an operator 193 controlled by a pattern control drum.

The stop plate 182 has a two-stepped cam surface at 194 and 195 operable to engage the pawl 76. When in the position shown in FIG. 16, with the surface 194 in registry with the pawl 76, the pawl is free to fully engage the teeth of the ratchet 78. When the stop plate 182 is displaced counterclockwise, as shown in FIG. 18, the surface 195 engages under the pawl 76 so as to cause it to partially disengage the teeth on the ratchet 78. This partial disengagement of the teeth does not affect the normal indexing of the ratchet by the pawl 76 until the foreshortened tooth 178 passes into registry with the pawl 76. When this occurs, the pawl 76 cannot engage the foreshortened tooth 178 because of the stop surface 195, and the indexing of the pattern drum is arrested. When it is desired to resume indexing of the drum 61, the stop plate 182 is displaced to the position shown in FIG. 16 which places the surface 194 in registry with the pawl, permitting it to engage the foreshortened tooth 178, whereupon normal indexing of the pattern drum resumes.

The stop plate 183, on the other hand, is provided with a three-stepped cam surface identified at 196, 197, and 198. The surfaces 196 and 197 perform the same function with respect to the pawl 77 as the surfaces 194 and 195 perform with the pawl 76. The surface 198, on the other hand, serves to instantaneously arrest indexing of the pattern drum by disengaging the pawl 77 from all of the teeth of the ratchet 79. Thus when the pawl 77 is in registry with the surface 196, the pattern drum indexes continuously so long as the pawl 76 is operated. When the surface 197 is registered with the pawl 77, the indexing continues until the half tooth 179 passes into registry with the pawl 77. When the surface 198 is in registry with the pawl 77, the indexing of the pattern drum is arrested.

In order to provide for wide pattern selectivity in the knitting machine without need for changing the jack arrangement in the cylinder or in the pattern drum, plural patterns are set up into the pattern drums to be selected by suitable camming on the front drum.

A particular pattern is rendered operative when the associated stops 111 are withdrawn to permit the levers 101 associated with said stops to engage against the pattern jack butts. The stops 111 which are not withdrawn inactivate the remaining levers 101 so as to cancel the remaining patterns. Inasmuch as fancy patterns embrace only a limited number of courses, it is necessary to use only a segment of the circumference of the pattern drum to provide such patterns. In the present instance, as shown in the development of the drum shown in FIG. 6, the fancy patterns are confined to half segments of the drum.

To prevent the pattern from both pattern beds of the pattern drum 61 from appearing inadvertently, the foreshortened teeth 178 and 179 on the ratchet wheels 78 and 79, which normally arrest the indexing of the drum as discussed above, are positioned in advance of each pattern segment of the drum to stop the drum in advance of the pattern. Thus, to re-initiate the indexing of the drum, the pawl stop 91 must be actuated to permit the pawl 76 or 77 to engage the foreshortened tooth. The pawls 76 and 77 are actuated to initiate the formation of the desired fancy pattern, and the indexing of the drum automatically stops at the next foreshortened tooth. Thus, at the end of the formation of the desired fancy pattern, the pattern drum 61 is 180 from the desired starting point in the next stocking. This 180 displacement of the pattern drum may be accomplished any time during the formation of the remainder of the stocking simply by actuating the stops 111 associated with the selector slides so that all of the steps are efiective to prevent actuation of the slides as the drum is indexed back to the desired starting point.

Thus, it is apparent that a single pattern drum 61 provides a selection of fancy patterns simply by changing the cams associated with the push rods 115 to actuate the stops 111, and the cams controlling the pawl stop mechanism 91. A similar arrangement may be provided on the pattern drum 62, but it is preferred to set up patterns on the drum 62 which are of infinite length and therefore are continuous about the entire circumference of the pattern drum.

Thus, the present invention provides means for in dexing a pattern drum of a knitting machine in accurately timed relation to the needle cylinder so as to enable displacement of the cams or slides controlling the knitting instrumentalities at the proper times in relation to the rotational position of the needle cylinder. The invention enables removal and replacement of the drum for changing the set-up thereof, the replacement being effective automatically to assure properly timed relationship between the drum and the cylinder. The novel indexing arrangement enables stopping of the pattern drum at any selected point and resumption of indexing of the drum automatically in properly timed relation.

The invention has been described in connection with an embodiment wherein the pattern drum controls the selection of jacks by the operation of selector slides, the drum including two pattern jacks for each revolution of the needle cylinder. By the same token there are two ratchet Wheels. It is within the scope of the invention to provide a greater number of pattern jacks for each revolution of the cylinder with a like number of ratchet wheels, each controlled from a separate cam track carried for rotation in synchronism with the knitting needle cylinder. The invention may also be used for controlling other pattern drums which must be accurately timed with relation to the needle cylinder and which may be removed from the knitting machine for changing the set-up thereof.

While a particular embodiment of the present invention has been herein illustrated and described it is not intended to limit the invention to such disclosure but changes and modifications may be made therein and thereto within the scope of the following claims.

I claim:

1. In a circular knitting machine having a rotary needle cylinder with a driving gear therefor, needles and jacks carried by said cylinder and having butts, actuators in the form of cams and slides selectively engaging said butts for displacing said needles, selected actuators being mounted for selective displacement radially of said cylinder, and at least one pattern drum for operating said selected actuators; means for indexing said drum at least twice for a revolution of said cylinder comprising at least two drum-advancing devices, each device comprising a ratchet wheel fixed to said drum and having a tooth length corresponding to the distance said drum is indexed for each revolution of the cylinder, and a separate pawl engageable with said teeth and operable to advance the ratchet wheel and drum a distance less than the distance of one tooth, means to operate the pawls of said devices in sequence so that the drum is indexed the distance of one tooth in steps, whereby disengagement of any pawl from the teeth prevents completion of the indexing and arrests the indexing of said drum.

2. A circular knitting machine according to claim 1 wherein each pawl is indexed the distance of one-half 10 tooth, so that the drum is indexed a full tooth in two steps, the displacement of the drum by each pawl effecting engagement of the other pawl behind its next tooth on the ratchet.

3. A circular knitting machine according to claim 2 wherein said means to operate the pawls comprises a separate cam track for each pawl carried on said driving gear, the cam tracks having a single rise, a follower for each cam track connected to the associated pawl and operable to effect said half-tooth displacement, said rises and followers being positioned to effect an index of said drum every half-revolution of said cylinder.

4. A circular knitting machine according to claim 3 wherein the butts engaged by said selected actuators are disposed in groups extending about a portion of said cylinder, said pattern being indexed to displace each actuator during the portion of said cylinder revolution when the group, which would otherwise interfere with the displacement, is out of registry therewith.

5. In a circular knitting machine having a rotary needle cylinder, and a pattern drum operable to be indexed twice for every revolution of said cylinder; means to index said drum comprising two ratchets fixed to said drum, each ratchet having teeth of a length corresponding to twice the distance of each index, a pawl for each ratchet, separate means to displace each pawl the distance of a half tooth comprising a pawl carrier, and means to operate said carriers in alternation every half revolution of said cylinder whereby one pawl and ratchet is effective only during alternate half-revolutions of said cylinder and the other pawl and ratchet is effective only during the remaining half-revolutions of said cylinder.

6. A circular knitting machine according to claim 5 wherein said means to operate the pawl carriers comprise cam means fixed relative to said cylinder for simultaneous rotation therewith, each cam means operating to displace its associated pawl at a predetermined point in the revolution of said cylinder.

7. A circular knitting machine according to claim 5 wherein at least one of said ratchets includes a radially foreshortened tooth, and including stop means to displace the associated pawl out of the path of said foreshortened tooth whereby the indexing of said drum is arrested when said pawl passes into registry with said foreshortened tooth.

8. A circular knitting machine according to claim 6 including stop means to displace one of said pawls out of the path of the teeth of said ratchet to thereby arrest indexing of said drum.

References Cited by the Examiner UNITED STATES PATENTS 1,969,853 8/1934 Page 66-50 2,040,946 5/ 1936 Marshall et al 66-50 2,164,118 6/1939 McAdams M 60-50 X 2,317,268 4/1943 Green 66-50 X 2,378,315 6/1945 Minton 66-50 2,460,487 2/1949 Bristow 66-50 2,726,525 12/1955 Haddad 66-50 2,754,668 7/1956 Deans et al 66-154 X 2,756,575 7/1956 Haddad 66-50 X 2,764,006 9/1956 Lawson et a1 66-50 X MERVIN STEIN, Primary Examiner.

R. FELDBAUM, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3,289,437 December 6, 1966 Peter A. Mahler It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 6, line 3, after "162" insert cooperates with the next thirty slides of the selector slide Signed and sealed this 26th day of September 1967.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. IN A CIRCULAR KNITTING MACHINE HAVING A ROTARY NEEDLE CYLINDER WITH A DRIVING GEAR THEREFOR, NEEDLES AND JACKS CARRIED BY SAID CYLINDER AND HAVING BUTTS, ACTUATORS IN THE FORM OF CAMS AND SLIDES SELECTIVELY ENGAGING SAID BUTTS FOR DISPLACING SAID NEEDLES, SELECTED ACTUATORS BEING MOUNTED FOR SELECTIVE DISPLACEMENT RADIALLY OF SAID CYLINDER, AND AT LEAST ONE PATTERN DRUM FOR OPERATING SAID SELECTED ACTUATORS; MEANS FOR INDEXING SAID DRUM AT LEAST TWICE FOR A REVOLUTION OF SAID CYLINDER COMPRISING AT LEAST TWO DRUM-ADVANCING DEVICES, EACH DEVICE COMPRISING A RATCHET WHEEL FIXED TO SAID DRUM AND HAVING A TOOTH LENGTH CORRESPONDING TO THE DISTANCE SAID DRUM IS INDEXED FOR EACH REVOLUTION OF THE CYLINDER, AND A SEPARATE PAWL ENGAGEABLE WITH SAID TEETH AND OPERABLE TO ADVANCE THE RATCHET WHEEL AND DRUM A DISTANCE LESS THAN THE DISTANCE OF ONE TOOTH, MEANS TO OPERATE THE PAWLS OF SAID DEVICES IN SEQUENCE SO THAT THE DRUM IS INDEXED THE DISTANCE OF ONE TOOTH IN STEPS, WHEREBY DISENGAGEMENT OF ANY PAWL FROM THE TEETH PREVENTS COMPLETION OF THE INDEXING AND ARRESTS THE INDEXING OF SAID DRUM. 